Software Technology for Medical device communication and charging assembly for implantable signal generators and associated methods

Invented by Jon Parker, Yougandh Chitre, Andre B. Walker, Nevro Corp

The Nevro Corp invention works as follows

Background for Medical device communication and charging assembly for implantable signal generators and associated methods

Neurological stimulations have been created to treat pain, movement disorders and functional disorders as well as cancer, heart disorders, and other medical conditions. Implantable neurological stimulation systems usually have an implantable signal generator (sometimes called an?implantable pulse generation?). Or?IPG? It is connected to one or more leads that transmit electrical signals or pulses to neuromuscular tissue. Many neurological stimulation systems that stimulate the spinal cord (SCS), for example, have cylindrical leads. They include a body with a circular cross section and multiple conductive rings at the distal end. The conductive rings act as contacts or electrodes to transmit electrical signals to patients. SCS leads can be implanted surgically or percutaneously using a needle that is inserted into the epidural area. Stylets are often used to assist with this procedure.

The signal generator transmits electrical signals to the electrodes once they are implanted. This in turn modifies the function of the patient?s nervous system. For example, it alters the patient’s response to sensory stimuli or alters the motor-circuit output. The electrical signals can create sensations that alter or mask the patient’s pain sensations. Patients may report feeling tingling, or paresthesia, which is more pleasant than the pain sensation. Patients may also report feeling relief from pain without experiencing paresthesia or any other sensations. The terms ‘pulses’ and?signals are used herein. Unless otherwise stated, the terms?pulses? and?signals are interchangeable. These terms can be interchanged to refer to any waveform shape, continuous or discontinuous, such as square waves or triangle waves, sawtooth or other sinusoidal waves.

The implantable signal generator usually includes a communication antenna that allows the operational parameters of a stimulation system to change without the need for a hard wired external link. An implantable signal generator often includes a charging coil, which allows the battery to be charged from an external source. The performance of the stimulation system can be affected by the design of the communication antenna, the charging coil, as well as their location within the implantable sign generator. It can be difficult to update operational parameters or charge the implantable signal generator if the antenna or the coil is not properly positioned. In many systems, it is difficult for patients or operators to position external devices correctly to transmit signals to an implantable signal generator. Poor coil design and shielding interference can reduce the charging process’ efficiency and increase heating. These and other drawbacks are common in older systems.

The present technology is directed to medical device communication and charging systems, but more specifically to implantable neuromodulation systems communication and charging assembly. Implantable signal generators with communication antennas and/or charge coils in the header of the signal generator are at least some examples of the current technology. You can make the communication antennas in many ways to improve, enhance, strengthen, and/or generate better signal reception. You can design, shape and position the charging coils to increase charging efficiency and reduce heat generation. Other embodiments allow for different configurations and components. Other embodiments might eliminate certain components or procedures. The current technology may also include associated devices, systems and procedures. 1-12. FIG. 1-12 describes several aspects of systems that are configured according to the disclosed technology. 1. Then, we will discuss features specific to certain charging and communication assemblies with reference to FIGS. 2-12.

FIG. “FIG. A signal delivery device 110 may be included in the overall patient system 100. This device is typically placed within the patient’s spinal chord midline 189 and connected to a signal generator 101 (e.g. a pulse generator). After implantation, the signal delivery device 110 contains features that allow for therapy delivery to the patient 190. The signal generator 101 is connected to the signal delivery system 110 directly or via a signal link or extension 102. A further representative embodiment of the signal delivery device 110 may include one or more extended leads or lead bodies (111). The terms “lead” and “lead body” are used herein. The terms?lead? and?lead bodies? are interchangeable. Any of the many suitable substrates or support members that can carry devices to provide therapy signals to patients 190. The lead or leads 111 may include one or more electrodes, or electrical contacts, that transmit electrical signals to the patient’s tissues, for example, in order to provide pain relief. Other embodiments of the signal delivery device 110 include other structures (e.g. a paddle) which can also direct electrical signals or other types to the patient 190.

The signal generator 101 transmits signals (e.g. electrical signals or therapy messages) to the signal delivery system 110. These signals can up-regulate or stimulate or excite target nerves and/or downregulate (e.g. block or suppress them). To?modulate?, as used herein and unless noted otherwise. Provide?modulation? to the target nerves is generally any of the above effects. A machine-readable (e.g. computer-readable) medium can be included in the signal generator 101 that contains instructions for creating and transmitting appropriate therapy signals. The signal generator 101, and/or any other elements of system 100, can include one or more processors 107, memory units 108, and/or input/output devices (not shown). Computer-readable media and/or other components can contain computer-executable instructions that allow for the provision of therapy signals and guidance information to position the signal delivery device(s), 110. Additionally, other functions associated with the process can be executed by the signal generator 101. Multiple elements and/or subsystems can be included in the signal generator 101. This is for example, to direct signals according to multiple signal delivery parameters. The entire signal generator 101 can be carried in one housing as shown in FIG. 1 or in multiple housings.

In some embodiments, the signal generator 101 can receive power from an external power source. External power source 103 can transmit power using electromagnetic induction (e.g. RF signals) to the implanted signal generation 101. An example of an external power source 103 could include a coil 104 which communicates with the internal coil (not illustrated) within the implantable pulse generation 101. For ease of use, the external power source 103 may be carried.

An external stimulator (or trial modulator) 105 can be connected to the signal delivery system 110 in at least some cases, before the signal generator 101 is implanted. A practitioner, such as a doctor or company representative, can use the trial module 105 to adjust the therapy parameters to the signal delivery system 110 in real-time and choose the most effective parameters. These parameters may include the location where the electrical signals are emitted as well as the characteristics and frequency of the signals delivered to the signal delivery system 110. A cable assembly 120 is used to connect the trial module 105 to signal delivery device 110. This is a common procedure. In an initial position, the practitioner can check the effectiveness of the signal delivery system 110. The practitioner can then remove the cable assembly 120 (e.g. at connector 122), and reposition the signal distribution device 110 before applying the electrical therapy again. The process can be repeated until the practitioner achieves the desired position of the signal delivery device 110. The practitioner can move the partially-implanted signal delivery element 110 by disconnecting the cable 120. In some embodiments, it may not be possible to perform the iterative process for repositioning signal delivery device 110 or adjusting therapy parameters.

The practitioner can then implant the implantable signal generator 101 in the patient 190 after a trial period using the trial modulator105. After the signal generator 101 has been implanted, the signal delivery parameters can be changed using a wireless physician?s programmer 117 (e.g. a physician?s laptop, remote, etc.). Wireless patient programmer 106 and/or wireless physician’s programmer 117 (e.g., patient’s laptop, remote, etc.) The patient 190 generally has less control than the practitioner.

FIG. “FIG. The can 204 could include a rectangular shell 206 and an oval-shaped lid 208. The lid 208 and shell 206 can both be made of titanium. A weld joint (210) can connect the lids 208 and 206. Other embodiments allow the shell 206 or lid 208 to be made from other metals or alloys. A weld joint 210 can join the lid 208 to the shell 206. The lid 208 may include multiple feed-throughs (212) for electrical communication between header 202, can 204 and can 204 in any of these embodiments.

Header 202 can contain a charging and communications assembly 214, first receiving element (216 a) and second receiving element (216 b) (collectively, receiving elements 212). One or more output terminals, or contact assemblies 218, can be included in the receiving elements 216. These are used to connect to the signal delivery device 110 (FIG. 1), or the lead extension (FIG. 1). A support element 220 can be included in the charging and communication assembly 214. It will carry a communication antenna 222, and a charging coil 226. The communication antenna 223 includes two curved connectors (223 a, 223 b). The support element 220 and the communication antenna 223, as well as the charging coil 224, can be bent, positioned and/or modified to improve the performance of the implantable signals generator. However, they must fit within the parameters of the header 202, as described below. Multiple wires 226, which can be extended upwardly from the can 204, can be connected to the individual contact assemblies 218 and 223 via the feed-throughs 213. They can also couple to the curved connectors 223 and the charging and communication assembly 221 via bushings 228. Each bushing is identified as a 128 a or 228b.

The wires 226 provide electrical connections between components in the header 202. These include the charging coil 224 or the communication antenna. There are also components within the can204. For example, a battery, controller, or 230. To provide power to the implantable signal generator 200 via receiving elements 216, the battery 230 can electrically be coupled to the controller232 and the output terminals/contact assemblies 218. The charging coil 224 can be used to recharge the battery 230. The controller 232 can electrically be coupled to the contact assembly 218 and battery 230. It can also include a processor 234, memory 236 and electronic circuitry. These electronic components can control and/or operate the implantable signal generator. The memory 236 may contain computer-readable instructions. These instructions can include operating parameters as well as instructions for controlling the operation of the implantable sign generator 200. The charging coil 224 converts electromagnetic energy (e.g. a magnetic flux) to electrical current that charges the battery 230. The communication antenna 228 can receive signals that relate to the operation and control of implantable signal generator 200. The communications antenna 224 can receive signals that are related to operating parameters, such as the frequency and duration of the modulation signals, for the implantable sign generator 200. These signals can then be sent to controller 232. The controller 232 is capable of controlling the delivery of electricity to the receiving elements 216.

FIG. 3. This is an isometric view showing a representative charging coil (224) with a pair wire loops (302 each, identified individually as a first and second wire loop 302 respectively), in accordance to another embodiment of the current technology. Each wire loop 302 can be made from a wire. The first wire 304a and second wire 304b can be made of a variety suitable metals and metal alloys, such as copper, silver coated copper or gold coated copper, and/or gold, silver or platinum, and/or any other suitable metals and metal alloys. The first wire 304a has a 306 a first and 307 a second ends. Similar to the first wire 304a, the second wire has a first ending 306 b as well as a second ending 307 b. The first end 306 of the first wire, 304 a, and the first 306 of the second wire, 304-b, are crimped together at 228 a. The second end 307a of the first wire 306 a and the second 307b of second wire 307b are crimped together in the second bushing 228, b. The two loops 302a and 302b are connected in parallel. The illustrated embodiment has two wires 304. Other embodiments may include additional wires and/or filers and/or multifiler wires. A Litz wire with individually insulated wires that can either be woven or braided together into a bundle can also be included. One embodiment can have four wire loops, or filers in addition to the two wires 304 in the illustrated embodiment.

The wire loops can be made by wrapping the first wire, 304a, around a spindle (not illustrated), removing the spindle and wrapping the second wire, 304b around a spindle multiplely, removing and laying the wire loops, 302a and 302b next to one another, and then coating them with an insulator, 310. Other embodiments allow the first and second wires 304a and 304b to be wrapped around the spindle simultaneously. The resulting wire loops will have the first and second wires 304a in contact along their entire lengths. To hold the wire loops 304 a, 304 b at their respective ends, the first and second ends 306a,306b and the third ends 307a,307b can be wrapped around wire loops 302. The wire loops can then be connected to support element 220 (FIG. 2), which will be explained further below.

Inductive power generation using single wire loops can generate more heat than single wire loops due to the electromagnetic properties of inductive charging (e.g. the skin effect). Multiple wires and loops can reduce the skin effect, which in turn will result in a decrease in heat generation and/or an increase in inductive charging capabilities. The resistance of the charging coil may be chosen to reduce the skin effect in some embodiments. A charging coil may have resistances ranging from 2 ohms up to 10 ohms in one embodiment. Other embodiments of charging coils may have resistances that are greater than 10 or lower than 2 ohms. Particular embodiments allow the pair of wires (304) to be wrapped around the spindle for a specified number of times. This is based on the size, shape, and/or electromagnetic characteristics the implantable signal generator 200 (FIG. 2), and the external power source (FIG. 1), and/or any other components of the patient-system 100 (FIG. 1). In one embodiment, the wires 304 can be wrapped around 30 times. Other embodiments allow the wires 304 to be wrapped around the spindle fewer or more times.

The charging coil can be bent to meet the requirements of operational performance and fit within the header (FIG. 2). The support element 220 (FIG. 2) can be shaped to support the charging wire 224. This will allow for a secure connection between the support element 220 (FIG. FIG. FIG. 3. The charging coil 224 is a rectangular shape that corresponds to the header 202 and a portion 220 of the support element (FIG. 2) is similar to (e.g. matches) this rectangular shape. Other embodiments of the charging element 224 and/or support element 220 may have other shapes, such as a circular, square, or oval to improve the performance and/or fit within the header 200 of the implantable signal generator200 (FIG. 2).

FIG. “FIG. You can make the communication antenna 222 from any number of metals and metal alloys, including copper, silver-coated copper, gold-coated copper, silver, gold, silver, platinum, and/or other suitable metals. One embodiment of the communication antenna 222 is made from magnet wire bent or formed into the rectangular shape in FIG. 4. The communication antenna 222 is able to be tailored to offer specific communication capabilities, and fit within the implantable sign generator 200 (FIG. 2). FIG. 2: The support element 220 (FIG. 2. can be shaped to match (e.g. closely match) the communication antenna 222. The curved connectors 223a, 223b can wrap around support element 220 as described below. The first curved connector 223, a can contain a first receiving cavity (404 a) and the second curved connector 223, b can contain a second receiving cavities (404 b). The receiving cavities 404a and 404b can be configured individually to receive individual wires 226 (FIG. 2) as described below.

FIG. “FIG. The illustrated embodiment shows the communication antenna 222, which is connected to the first receiving surface 502 in FIG. 5. The curved connectors 223, 223 and 223b are at most partially curved around a portion 220 of the support element. The feed-throughs 212 can be relieved of stress by bending the connectors 223a, 223b (FIG. 2). FIG. The adhesive elements 506 (FIG. The illustrated embodiment shows the charging coil 228 and the communication antenna 222, which are attached to the support element 220 using adhesive elements or curved connectors. However, other fasteners and features may be used. Fastening clips and tabs can be attached to the support element 220. They can be used to engage the communication antenna 222/224 and/or charging coil 224. You can mold or form the support element 220 to include grooves and/or flexible tabs which can attach the communication antenna (222) and/or charging coil (224).

Referring To FIG. “Referring to FIG. 2 and FIG. 6 Together, the communication antenna 222, and the charging coil 220 carried by support element 220 can be connected to electrical components within can 204 by connecting individual wires 226, to the curved connectors 213, 223 b, and bushings 228. As shown in FIG. 2, the wires 226 connecting to the curved connectors 223, 223 b, can be bent. 2. To align with the curved connectors 223, 223 b, 223, 223 a, 223, 223 b. The wires 226 can be used to hold the support element 220 or the receiving elements 221 in the position illustrated in FIG. 2. FIG. 2.) can be further processed to cover the support element 220 (FIG. The epoxy can be used to seal the header 202, wires 226, bushings 228, charging coil 224, communication antenna 222, and at most a portion the receiving elements 216.

FIG. “FIG. 7” is an isometric view showing a portion 200 of the implantable signal generator. The header 202 is configured according to a further embodiment. The illustrated embodiment includes an epoxy volume 702 with receiving inlets 704 (individually identified as a first receiving input 704 a or 704b). The receiving inlets 704 allow access to the receiving elements 216, 216, and 216 b. This allows for a lead 111 (FIG. 1. or a lead extension of 102 (FIG. 1) must be connected to the signal generator. You can form the epoxy volume 702 or the receiving inlets 704. In many ways. The epoxy volume 702 can be made by inserting a temporary plug (not illustrated) into each receiving element 216. After that, dip the header 202 into epoxy (e.g. an epoxy-filled mold). Other embodiments allow for the header 202 to be covered in other materials, such as molded plastic. The header 202 can be cast and/or pre-molded in some embodiments.